This invention relates to a lighting device and control thereof; in particular to a lighting device operable to produce a flash.
In the photographic industry, dedicated on and off-camera flash units are used to illuminate scenes for a fraction of a second to allow a camera to obtain a good photographic image in poor light conditions. These flash units are typically triggered to coincide with the camera shutter by an electrical signal from the camera itself. Studio lights differ from flash lights in that they provide a continuous level of illumination which allows the user to “shoot what they see” taking out the guess work and ‘trial and error’ process associated with flash. Additionally this means continuous light can be used for both photography and video. However they are typically unable to match the instantaneous light levels of a dedicated flash unit, since to do so would require excessive cost and power.
Modern flash/strobe units sometimes include “modelling lights” consisting of an additional light source in addition to the flash light source. The purpose of such additional lights is to compose the image and pose the ‘model’ so the photographer can judge where shadows and highlights will fall in advance of the flash. From a human physiology point of view, this is an easier process for a subject to endure, as high power continuous lighting can be uncomfortable and sometimes carries a health risk to the subject. Such an arrangement also allows the camera to autofocus, and enables the model to pose and prepare for the flash and control pupil dilation without over reacting to the brightness of the flash.
However, the use of a second light source independent of the primary strobe or flash may affect the outcome of the photograph as they necessarily use a different bulb from the main flash unit at a lower intensity and varying correlated colour temperature (CCT), often with lower colour rendering index (CRI) accuracy—this throws off the skin tone, and renders inaccurate light readings taken before the flash is fired. It also limits the usefulness of any approximation of shadow and highlights perceived which, due to the positioning and light characteristic differences of the modelling light, will noticeably vary from the primary strobe/flash unit.
An improved solution is desired.